/*
 * Copyright (c) 2001-2008 Caucho Technology, Inc.  All rights reserved.
 *
 * The Apache Software License, Version 1.1
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 *
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 *
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in
 *    the documentation and/or other materials provided with the
 *    distribution.
 *
 * 3. The end-user documentation included with the redistribution, if
 *    any, must include the following acknowlegement:
 *       "This product includes software developed by the
 *        Caucho Technology (http://www.caucho.com/)."
 *    Alternately, this acknowlegement may appear in the software itself,
 *    if and wherever such third-party acknowlegements normally appear.
 *
 * 4. The names "Hessian", "Resin", and "Caucho" must not be used to
 *    endorse or promote products derived from this software without prior
 *    written permission. For written permission, please contact
 *    info@caucho.com.
 *
 * 5. Products derived from this software may not be called "Resin"
 *    nor may "Resin" appear in their names without prior written
 *    permission of Caucho Technology.
 *
 * THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESSED OR IMPLIED
 * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
 * DISCLAIMED.  IN NO EVENT SHALL CAUCHO TECHNOLOGY OR ITS CONTRIBUTORS
 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY,
 * OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT
 * OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR
 * BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
 * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE
 * OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN
 * IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 *
 * @author Scott Ferguson
 */

package com.caucho.services.server;

import javax.servlet.ServletException;
import javax.servlet.ServletRequest;
import java.util.HashMap;

/**
 * Context for a service, to handle request-specific information.
 */
public class ServiceContext {
    private static final ThreadLocal _localContext = new ThreadLocal();

    private ServletRequest _request;
    private String _serviceName;
    private String _objectId;
    private int _count;
    private HashMap _headers = new HashMap();

    private ServiceContext() {
    }

    /**
     * Sets the request object prior to calling the service's method.
     *
     * @param request the calling servlet request
     * @param serviceId the service identifier
     * @param objectId the object identifier
     */
    public static void begin(ServletRequest request, String serviceName, String objectId) throws ServletException {
        ServiceContext context = (ServiceContext) _localContext.get();

        if (context == null) {
            context = new ServiceContext();
            _localContext.set(context);
        }

        context._request = request;
        context._serviceName = serviceName;
        context._objectId = objectId;
        context._count++;
    }

    /**
     * Returns the service request.
     */
    public static ServiceContext getContext() {
        return (ServiceContext) _localContext.get();
    }

    /**
     * Adds a header.
     */
    public void addHeader(String header, Object value) {
        _headers.put(header, value);
    }

    /**
     * Gets a header.
     */
    public Object getHeader(String header) {
        return _headers.get(header);
    }

    /**
     * Gets a header from the context.
     */
    public static Object getContextHeader(String header) {
        ServiceContext context = (ServiceContext) _localContext.get();

        if (context != null)
            return context.getHeader(header);
        else
            return null;
    }

    /**
     * Returns the service request.
     */
    public static ServletRequest getContextRequest() {
        ServiceContext context = (ServiceContext) _localContext.get();

        if (context != null)
            return context._request;
        else
            return null;
    }

    /**
     * Returns the service id, corresponding to the pathInfo of the URL.
     */
    public static String getContextServiceName() {
        ServiceContext context = (ServiceContext) _localContext.get();

        if (context != null)
            return context._serviceName;
        else
            return null;
    }

    /**
     * Returns the object id, corresponding to the ?id= of the URL.
     */
    public static String getContextObjectId() {
        ServiceContext context = (ServiceContext) _localContext.get();

        if (context != null)
            return context._objectId;
        else
            return null;
    }

    /**
     * Cleanup at the end of a request.
     */
    public static void end() {
        ServiceContext context = (ServiceContext) _localContext.get();

        if (context != null && --context._count == 0) {
            context._request = null;

            context._headers.clear();
        }
    }

    /**
     * Returns the service request.
     *
     * @deprecated
     */
    public static ServletRequest getRequest() {
        ServiceContext context = (ServiceContext) _localContext.get();

        if (context != null)
            return context._request;
        else
            return null;
    }

    /**
     * Returns the service id, corresponding to the pathInfo of the URL.
     *
     * @deprecated
     */
    public static String getServiceName() {
        ServiceContext context = (ServiceContext) _localContext.get();

        if (context != null)
            return context._serviceName;
        else
            return null;
    }

    /**
     * Returns the object id, corresponding to the ?id= of the URL.
     *
     * @deprecated
     */
    public static String getObjectId() {
        ServiceContext context = (ServiceContext) _localContext.get();

        if (context != null)
            return context._objectId;
        else
            return null;
    }
}
